1. Field of the Invention
The present invention relates to an IC test system for testing whether or not characteristics of an IC satisfy the predetermined standard, and relates to a storage medium for the same.
2. Description of Related Art
In general, an IC (Integrated Circuit), an LSI (Large Scale Integrated circuit) and the like (hereinbelow, these will be described only as xe2x80x9can ICxe2x80x9d) have some dispersion in characteristics by each product when they are mass-produced. Then, an IC test system has been utilized for testing whether or not characteristics of an IC satisfy the predetermined standard.
An example of construction of a former IC test system according to an earlier development is shown in FIG. 5. In this drawing, the IC test system 100 comprises an input device 110, an output device 120, a management device 130, a control device 180 and an IC tester 190.
The input device 110, such as a keyboard or a mouse, to which an operator inputs a microprogram for simulating an operation of the IC tester 190 which will be explained below, and a data for identifying a test pattern signal which is to be applied to an IC. The output device 120, such as a display or a printer, outputs the situation of simulation of the microprogram simulator 134, or conditions or a result of an actual operation of the IC tester 190. The IC tester 190 and the microprogram simulator 134 will be explained below.
The management device 130 outputs control signals to other elements of the IC test system 100, and manages the whole of the IC test system 100. The management device 130 comprises a management section 131, an analysis section 132, a storage area for storing hardware/register information 133 and a microprogram simulator 134.
The management section 131 comprises a management program 131a, and manages data communication between the analysis section 132 and the control device 180 which will be explained below, in accordance with a process described in the management program 131a. 
The analysis section 132 comprises an application program 132a, and analyzes a test result obtained by operating the IC tester 190 which will be explained below, in accordance with the process described in the application program 132a. 
The microprogram simulator 134 simulates the operation of the IC tester 190. The operation of the microprogram simulator 134 will be explained below. The hardware/register information 133 comprises information about simulation condition and a simulation result of the microprogram simulator 134.
The control device 180 is connected to the management section 131 and the IC tester 190. The control device 180 analyzes the control signal which is input by the management section 131, according to the control program 181, and controls the IC tester 190 in accordance with the analysis result.
The IC tester 190 actually tests characteristics of an IC under the control by the control device 180. The IC tester 190 comprises a test pattern signal generator (which is not shown in the figures) which applies a predetermined test pattern signal for testing the electric characteristics of the IC, to the IC as a product.
The IC tester 190 comprises a storage area for storing hardware/register information 191 separate from the hardware/register information 133. The hardware/register information 191 comprises information about a test condition and a test result of the IC tester 190.
Then, the operation of the IC test system 100 will be explained. At first, when an operator inputs a data through the input device 110, for identifying a test pattern signal to be applied to an IC, the analysis section 132 analyzes the data to output the analysis result to the management section 131. When the management section 131 receives the analysis result, the management section 131 outputs the analysis result to the control device 180.
The control device 180 executes the control program 181. Further, the control device 180 processes the analysis result obtained by operating the analysis section 132, and controls the IC tester 190 in accordance with the processed result. The IC tester 190 applies a test pattern signal to an IC in accordance with the control by the control device 180, and outputs a test result, that is, a response from the IC, to the control device 180.
The control device 180 outputs the test result obtained by operating the IC tester 190 to the management section 131. When the management section 131 receives the test result, the management section 131 outputs the test result to the analysis section 132. The analysis section 132 analyzes the test result and outputs an analysis result to the output device 120. As described above, an actual test of an IC is carried out.
On the other hand, the microprogram simulator 134 simulates the operation of the IC tester 190. The operation of the microprogram simulator 134 will be explained, in view of the flowchart shown in FIG. 6. At first, the microprogram simulator 134 executes a translation process for translating a microprogram which is input through the input device 110, into the executable program codes (step S600).
Then, the microprogram simulator 134 changes the contents of the hardware/register information 133 in accordance with the program codes formed by translating the microprogram (step S601). Here, when the contents of the hardware/register information 133 are changed by an operator through the input device 110 (step S602; YES), the process is back to the step S600, and the microprogram simulator 134 executes the translation process.
When the contents of the hardware/register information 133 are not changed (step S602; NO), the microprogram simulator 134 executes a simulation process (step S603). The microprogram simulator 134 simulates the operation of the IC tester 190, and outputs the simulation result to the output device 120.
As described above, the microprogram simulator 134 is not required to work with the analysis section 132 and the management section 131. Therefore, the microprogram simulator 134 can operate separately. Moreover, an operator can confirm the operation of the IC tester 190 without actually using of the IC tester 190, evaluate the microprogram which the operator programmed, and design a test pattern signal for being applied to an IC in accordance with the simulation result.
However, in this IC test system 100 according to an earlier development, because the management section 131 manages the hardware/register information 133 and the hardware/register information 191 separately, the simulation result of the microprogram simulator 134 cannot be analyzed by the analysis section 132 in real time. Further, the microprogram which is input for the simulation, cannot be reused as a microprogram for an actual test operated by the IC tester 190 immediately. Therefore, the working efficiency of an operator was deteriorated.
Moreover, the IC test system 100, as a whole, requires many storage areas, because the IC test system 100 sets the hardware/register information 133 which is exclusively used by the microprogram simulator 134, separate from the hardware/register information 191 of the IC tester 190.
An object of the invention is to provide an IC test system which improves the working efficiency of an operator. Concretely, an object of this invention is to provide an IC test system which enables the simulation result to be analyzed by an analysis section in real time, and enables a microprogram which is input for setting the simulation condition, to be reused for setting the actual test condition, by making the microprogram simulator and the analysis section share the information about the simulation and the information about the test.
In accordance with the first aspect of the invention, an IC test system comprises:
a test pattern signal applying section for applying a test pattern signal to an IC to be tested, in accordance with a test program;
a simulation section for simulating an operation of the test pattern signal applying section in accordance with a simulation program; and
a management device which is connected detachably with the test pattern signal applying section, for managing the operation of the test pattern signal applying section and an operation of the simulation section in accordance with a management program, for storing information about each operation of the test pattern signal applying section and the simulation section, and for managing one of the information about the operation of the simulation section and the information about the operation of the test pattern signal applying section in accordance with the other information.
Here, the test pattern signal applying section applies a test pattern signal to an IC to be tested according to the test program. The simulation section simulates the operation of the test pattern signal applying section according to the simulation program. The management device stores the information about the operation of the test pattern signal applying section and the operation of the simulation section, and manages the operation of the test pattern signal applying section and the operation of the simulation section.
The management device manages the operation of the test pattern signal applying section and the operation of the simulation section. A test condition and a test result of the test pattern signal applying section, and a simulation condition and a simulation result of the simulation section are managed mutually by the management device. Therefore, the simulation result can be analyzed in real time by the analysis section, and a microprogram which is input for setting the simulation condition can be reused as a microprogram for setting a test condition. Further, the working efficiency of an operator can be improved.
Furthermore, as opposed to an IC test system according to an earlier development, the simulation condition and the simulation result of the simulation section, and the test condition and the test result of the test pattern signal applying section are not required to be set separately. Therefore, it is possible that the whole of the storage areas can be effectively used.
The information about the operation of the simulation section may be a simulation result, and the information about the operation of the test pattern signal applying section may be a test result.
The information about the operation of the simulation section may be a simulation condition, and the information about the operation of the test pattern signal applying section may be a test condition.
Preferably, the information about the operation of the simulation section is a simulation condition and a simulation result, the information about the operation of the test pattern signal applying section is a test condition and a test result, in case that the test pattern signal applying section is connected with the management device, the management device manages the test condition of the test pattern signal applying section in accordance with the simulation condition of the simulation section, and in case that the test pattern signal applying section is detached from the management device, the management device manages the simulation condition and the simulation result of the simulation section in accordance with the test condition and the test result of the test pattern signal applying section.
More preferably, the management device further comprises a storage area setting unit for setting a storage area as a common storage area for storing the information about the operation of the simulation section and the information about the operation of the test pattern signal applying section or as a separate storage area for separately storing the information about the operation of the simulation section and the information about the operation of the test pattern signal applying section, in accordance with whether the management device is connected with the test pattern signal applying section.
Here, the management device comprises the storage area setting unit. The storage area setting unit sets a storage area as a common storage area for storing the information about the operation of the simulation section and the information about the operation of the test pattern signal applying section or as a separate storage area for separately storing the information about the operation of the simulation section and the information about the operation of the test pattern signal applying section, in accordance with whether the management device is connected with the test pattern signal applying section.
Therefore, an operator can operate only the simulation section separately, because the information about the operation of the test pattern signal applying section, and the information about the operation of the simulation section, are managed separately, even though the test pattern signal applying section is not connected with the management device.
More preferably, the simulation section controls the storage area for information about an operation set by the management device, so as to switch the storage area between the common storage area and the separate storage area.
Here, the simulation section controls the storage area of the management device so as to switch the storage area between the common storage area and the separate storage area. Therefore, it is possible that an operator can connect the test pattern signal applying section with the management device if necessary, and can feed the information about the simulation condition of the simulation section back to the connected test pattern signal applying section, even though the management device has previously operated only the simulation section without the connection with the test pattern signal applying section. Further, the operability of the IC test system can be improved. As a result, the working efficiency of an operator can be improved.
More preferably, in case that the storage area for storing the information about the operation of the simulation section and the information about the operation of the test pattern signal applying section is the common storage area, when at least one of the information about the operation of the simulation section and the information about the operation of the test pattern signal applying section is changed, the management device transmits the changed information to the test pattern signal applying section and the simulation section in real time.
Here, in case that the storage area for storing the information about the operation of the simulation section and the information about the operation of the test pattern signal applying section is the common storage area, when at least one of the information about the operation of the simulation section and the information about the operation of the test pattern signal applying section is changed, the management device transmits the changed information to the test pattern signal applying section and the simulation section in real time. Therefore, it is possible that the simulation condition of the simulation section can be reflected on the actual operation of the test pattern signal applying section immediately.
Moreover, when an operator sets the simulation condition, the operator can consider the actual test condition and the actual test result of the test pattern signal applying section in real time. Therefore, it is possible that the working efficiency of the operator for the simulation process can be much improved.
Still more preferably, in case that the storage area for storing the information about the operation of the simulation section and the information about the operation of the test pattern signal applying section is not common, the management device manages the information about the operation of the simulation section without reference to the management program.
Here, in case that the storage area for storing the information about the operation of the simulation section and the information about the operation of the test pattern signal applying section is not common, the management device manages the information about the operation of the simulation section without reference to the management program.
That is, the management device refers to a program for managing only the information about the operation of the simulation section instead of the management program, like a management program according to an earlier development, when the storage area for storing the information about the operation of the test pattern signal applying section and the information about the operation of the simulation section is not common.
Therefore, the IC test system can be realized at a low cost by a minimum change of a construction of an existing IC test system according to an earlier development, because it is possible that the management device can comprise a management program like an earlier development.
In accordance with the second aspect of the invention, the storage medium has a program recorded thereon, which is executable by a computer for controlling an operation of an IC test system, wherein the program comprises:
a program code for applying a test pattern signal to an IC to be tested;
a program code for simulating an applying operation of applying the test pattern signal to the IC to be tested;
a program code for managing the applying operation and a simulating operation of simulating the applying operation, and for storing information about the applying operation and information about the simulating operation; and
a program code for managing one of the information about the simulating operation and the information about the applying operation in accordance with the other information.
According to the second aspect of the invention, in order to control the operation of the IC test system, an operator can execute, in a computer, a program having the program codes for applying a test pattern signal to an IC to be tested, for simulating the applying operation, for managing the applying operation and the simulating operation, for storing information about the applying operation and information about the simulating operation, and for managing one of the information about the simulating operation and the information about the applying operation in accordance with the other information.
Moreover, the computer for executing the program stored in the storage medium operates like the IC test system of the first aspect of the present invention. Therefore, the IC test system in which the working efficiency of an operator can be improved and in which the whole storage areas can be effectively used, can be realized.